[Chandler-dev] [Sum] The Great Architecture Discussion of 2007

[Andi Vajda]

On Tue, 9 Oct 2007, Grant Baillie wrote:

>>> 4. implementing a generic database inside another generic database
>> 
>> That was the goal, originally. Not to have a hard compiled app against a 
>> hard compiled relational schema. If Chandler is to become a hard compiled 
>> application with a static schema, where all data types have to be 
>> determined in advance, then of course, the chandler repository is overkill 
>> and can be replaced by some specifically optimized, domain-specific, 
>> schema.
>
> I'm confused: How is what we have (where you have to throw out your data any 
> time the schema at either of 2 levels changes) different from the "hard 
> compiled app against a hard compiled relational schema"? (Apart from the word 
> "relational").

Not throw out. Migrate to a new schema. Just like in a relational database.
If you change the low-level layout (format), core schema, or app schema (table 
layout) someone needs to migrate the data. It might be apparently easier in a 
relational schema but not so once you've carefully optimized it and duplicated 
stuff left and right to get the desired performance. Essentially, it becomes 
harder once the 1-1 correspondance between programmer's view (kind/class) and 
SQL table is broken.

Andi..